Retinal pigment epithelium hyperplasia overlying pigment epithelial detachment in age-related macular degeneration can masquerade as neovascularization on optical coherence tomography angiography

PURPOSE: To report the image artifacts due to retinal pigment epithelium (RPE) hyperplasia overlying retinal pigment epithelial detachment (PED) in age-related macular degeneration (AMD), which can masquerade as neovascularization on optical coherence tomography angiography (OCTA). METHODS: A hospital-based, retrospective, and cross-sectional study. Twenty-two eyes from 16 patients with non-vascularized PED related to AMD were included in this study. All patients were examined by OCTA, spectral-domain optical coherence tomography, fluorescence angiography, and indocyanine green angiography. Vascular flow signals (VFS) on both the outer retinal slab of en face OCTA and cross-sectional OCTA and their correspondence with RPE hyperplasia were evaluated. RESULTS: Fifteen eyes (68.2%) showed VFS on both the outer retina slab of en face OCTA and cross-sectional OCTA, all corresponding to the RPE hyperplasia overlying PED. Among them, 12 eyes with lump RPE hyperplasia outside foveal avascular zone (FAZ) all showed obvious VFS on the outer retina slab of OCTA, and 3 eyes with scattered RPE hyperplasia outside FAZ showed VFS fragments. Of note, 4 eyes had accompanied RPE hyperplasia inside FAZ, and 7 eyes without RPE hyperplasia overlying PED showed no corresponding VFS on the outer retina slab of OCTA. Additionally, a round-like dark band at the edge of PED was observed in the outer retina slab on en face OCTA in 17 eyes (77.3%). CONCLUSIONS: RPE hyperplasia overlying PED in AMD can masquerade as neovascularization on OCTA. To avoid misdiagnosis and unnecessary treatment, this RPE hyperplasia-related image artifact should be considered when interpreting OCTA images.